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| #include<algorithm>
#include<iostream>
#include<iomanip>
#include<cstring>
#include<cstdlib>
#include<climits>
#include<vector>
#include<cstdio>
#include<cmath>
#include<queue>
using namespace std;
typedef long long LL;
inline const int Get_Int() {
int num=0,bj=1;
char x=getchar();
while(x<'0'||x>'9') {
if(x=='-')bj=-1;
x=getchar();
}
while(x>='0'&&x<='9') {
num=num*10+x-'0';
x=getchar();
}
return num*bj;
}
const int maxn=125,mod=45989;
struct Matrix {
LL n,m,a[maxn][maxn];
Matrix(LL n,LL m) {
init(n,m);
}
Matrix(LL n,LL m,char E) {
init(n,m);
for(int i=1; i<=n; i++)a[i][i]=1;
}
void init(LL n,LL m) {
this->n=n;
this->m=m;
memset(a,0,sizeof(a));
}
LL* operator [] (const LL x) {
return a[x];
}
Matrix operator * (Matrix& b) {
Matrix c(n,b.m);
for(int i=1; i<=n; i++)
for(int j=1; j<=b.m; j++)
for(int k=1; k<=m; k++)
c[i][j]=(c[i][j]+a[i][k]*b[k][j])%mod;
return c;
}
void operator *= (Matrix& b) {
*this=*this*b;
}
Matrix operator ^ (LL b) {
Matrix ans(n,m,'e'),a=*this;
while(b>0) {
if(b&1)ans=ans*a;
a*=a;
b>>=1;
}
return ans;
}
};
struct Edge {
int from,to,id;
};
LL n,m,len,s,t,from[maxn],to[maxn],ans=0;
vector<Edge>edges[maxn];
void AddEdge(int x,int y,int id) {
edges[x].push_back((Edge) {
x,y,id
});
}
int inv(int id) {
if(id&1)return id+1;
return id-1;
}
int main() {
n=Get_Int();
m=Get_Int();
len=Get_Int();
s=Get_Int()+1;
t=Get_Int()+1;
for(int i=1; i<=m; i++) {
int x=Get_Int()+1,y=Get_Int()+1;
AddEdge(x,y,2*i-1);
AddEdge(y,x,2*i);
from[2*i-1]=x;
to[2*i-1]=y;
from[2*i]=y;
to[2*i]=x;
}
Matrix M(2*m,2*m);
for(int i=1; i<=2*m; i++) {
int Now=to[i];
for(Edge& e:edges[Now]) {
int Next=e.to;
if(e.id==inv(i))continue;
M[i][e.id]=1;
}
}
M=M^(len-1);
for(Edge& out:edges[s])
for(Edge& in:edges[t])
ans=(ans+M[out.id][inv(in.id)])%mod;
printf("%lld\n",ans);
return 0;
}
|
